TRB’s Transportation Research Record: Journal of the Transportation Research Board, No. 2234 consists of 14 papers that explore improving resilience of critical infrastructure systems, material convergence and its determinants, defending transportation networks against attack, location of medical facilities, and site considerations for points of dispersing after biological terrorist attack.

This issue of the TRR also examines communicating with vulnerable populations, traffic information in emergency situations, relocating children in daytime no-notice evacuations, influence of departure time spans and corresponding network performance on evacuation time, turning movements in pedestrian crowds during emergency egress, evacuation network design, simulating vehicular–pedestrian mixed flows in a congested network, and hurricane evacuation planning.